Since his humble beginnings as a child of immigrant parents in Biddeford, Maine, Bernard Osher has become a prominent philanthropist widely known by the institutions that bear his name.

But when you meet the 91-year-old, who still is grounded by the values instilled in him when he was young, you might not guess that he is a man of great wealth and influence. Osher is attentive, approachable, self-effacing.

He still works five days a week — “I wouldn’t know what to do with myself [otherwise],” he half jokes during an interview — and he usually walks from home to his Financial District offices. The Bernard Osher Foundation is headquartered on the 40th floor of a high-rise with exquisite views of the Bay Bridge, Treasure Island and beyond.

While acknowledging that he has always worked hard — “I was working all the time, seven days a week; I paid attention to business” — Osher also likes to have fun. He enjoys skiing, fly-fishing and opera (he serves on the San Francisco Opera board), and he works out six days a week. He started piano lessons at age 80 (“I’m very much an amateur,” he concedes) and tried surfing at 84. His first attempt wasn’t great, but the next time, on a bigger, thicker board, “I looked pretty good on it.”

As a young college grad, Osher managed the family hardware and plumbing supplies store and operated a waterfront amusement park. He also followed his sister, Marion, to Wall Street, but not for long.

Osher moved to the Bay Area in 1963 and, with Marion and her husband, Herbert Sandler, co-founded “a small savings and loan association” that became World Savings, the second-largest savings institution in the U.S., when it was acquired by the Wachovia Corp. in 2006.

A collector of American paintings from the mid-19th and 20th centuries, Osher also put a lot of effort into building the auction house Butterfield & Butterfield, which he purchased in 1970 and sold to eBay for a reported $260 million in 1999.

“I never expected to sell the company to eBay,” he said. “It’s what they say — you have a lot of mazel,” Yiddish for luck.

Such success helped fuel the Bernard Osher Foundation, created in 1977 to support medicine, education and the arts. Osher also established the Bernard Osher Jewish Philanthropies Fund, a donor-advised fund of the S.F.-based Jewish Community Federation, for which he has served on the board and on various committees. Disbursements are “pretty well spread out to Jewish organizations … whatever appeals to us at the time,” Osher said. “We try to stay with them year after year.”

Barney, as he is known to friends, and wife Barbro have signed the Giving Pledge, joining some of the world’s richest people in dedicating the majority of their wealth to philanthropic causes.

Phyllis Cook, an Osher Foundation board member and former 25-year executive director of the S.F-based Jewish Community Endowment Fund, puts Osher “right up there at the top of my list” of those who have made a huge impact on the Jewish community. He is willing to deal with problems and needs, she said, and “does it in an understated way. He has made so many things happen.”

She cites the role that he and Barbro, who chairs the Osher Foundation board, played in funding the Osher Marin JCC. “That was a community that really hadn’t come together,” Cook said. “He helped build that campus.”

Likewise, he helped finance the $50 million reconstruction and expansion of the JCC of San Francisco in the early 2000s.

“Take any project — you name it,” Cook said, offering the Jewish Home’s new San Francisco Campus for Jewish Living as another example. “He is a major supporter of the Jewish community.”

The Bernard Osher Foundation has four primary focuses: Osher Lifelong Learning Institutes, now offered at 123 colleges and universities across the U.S.; the Osher Collaborative for Integrative Medicine, with centers at UCSF Medical Center, Harvard and five other universities; scholarship and fellowship programs, available at hundreds of higher learning institutions, including community colleges; and arts and educational programs in the Bay Area and Maine.

Osher holds close ties to his native state, which he still visits and where he owns a beachfront home. It was in Maine that Osher was inspired to start OLLI, the lifelong learning program. He was waiting to see a friend at the University of Southern Maine in Portland when “all of a sudden the door opens and I see 40 to 50 white-haired people” in a classroom, he recalled. The instructor, Rabbi Harry Sky, was a progressive leader and advocate for senior learning.

“I said, boy, this is a great thing,” Osher remembered. “That’s how it started.”

But his commitment to help others started way before that.

Osher, a longtime member of Conservative Congregation Beth Sholom in San Francisco, grew up with his four siblings in an Orthodox household in a town with one synagogue. His father exemplified the concept of tzedakah, always assisting those in need. People from small organizations (there were no large Jewish agencies at the time, Osher explained) would “come around and ask for $1 or $5 donations or more, and my father would give,” Osher said. “When I took over the hardware store, I would do the same thing.”

Osher “still holds the ethics that his father taught him. It’s an homage to his father,” said John Pritzker, the founding partner and director of an S.F.-based investment firm and himself a generous philanthropist and a Jewish communal and civic leader.

Pritzker has known Osher for more than 30 years and considers him a friend and mentor. A board member of the Osher Foundation, Pritzker believes that Osher asked him to join because “he wanted to teach me the right way to do philanthropy.”

Osher’s philanthropic method is “focused, and that’s really one of the lessons he has taught me,” Pritzker said. Rather than awarding small sums to many different causes (“He gets 400 solicitations a week,” Pritzker said), Osher gives impactfully. As evidence, OLLI programs continue to flourish all over the country, while the foundation’s scholar and fellow programs are now offered at more than 350 colleges and universities.

Looking back on his accomplishments, is Osher ever amazed? In typical fashion, he answers, “I say, ‘How lucky I am to be able to do all these things.’”

Part of Trailblazers, a series of profiles of Jewish men and women who build and sustain our Jewish community, supported by a generous donation from Carol and Norman Traeger.